Muffler.



M. THOMSON.

MUFFLBB.

APPLioATIoN FILED DBO. ao, 1912.

1,066,341. Patented July 1, 1913.

In Ventor Malcolm Thomson His aclttc'rng UNITED STATES PATENT oEErcE.

, MALCGLM THOMSON, OF SWAMPSCOTT, MASSACHUSETTS, ASSIGNOR TO GENERAL ELECTQIC CQMPANY, A ORPORATION OF NEW YORK..Y

MUFFLER.

. Specification of Letters Patent.

Patent-ed Julyi, 1913.

Application filed December 30, 1912. Serial No. 739,213.

T 0 all whom it may concern.' l

Be it known that l, MALCOLM THOMSON, a citizen of the'United States, residing at Swampscott, count-y of4 Essex, State of Massachusetts, have invented certain new and useful Improvement-s in Mulers, of which the following is a specificati-on.

The present invention relates to mutllers or silencers for exhaust gases of internal combustion engines.

The mul-ller or silencer forming the submatter o'f this application is based on the principle of lagging separated gas impulses, one behind thei other, as 'set forth in the United States patent to Elihu Thomson., 854,778, dated May e8, 1907.

The object of the invention is to improve the .construction and operation of such a muffler, particular reference being made to decreasing the size, weight and cost of constructing the saine.

One of the distinctive features of the present muffler resides in the fact that the gases flow in a double zig/Zag path instead of ollowing a spiral path as in the patent aforesaid.' Y

Other features of the invention will be set 'forth more fully'in the following description and'claims appended thereto.

In the accompanying 4drawing which illustrates one of the embodiments .of my invention, Figure l is a longitudinal section of my improved muffler; Fig. 2 is a plan View of the exhaust pipe showing the arrangement of 4theperforations; Fig. 3 is a cross-section takenl on line 3 3 of Fig.v 1; F ig. 4 is a cross-section taken on iine 4 4 of 1; Fi 5 is a'section taken on the vline 5 5 of Fig. 1, and Fig. fshows a number of m fliers connected in multiple to the same exhaust conduit.

7 indicates an exhaust conduit of suitable size that is connected to the'exhaust chamber yof the enginev'whose gases are to be Imulllled. This conduit should-be of such cross sectional area asto Apermit the gases from the engine to freely enter and pass therefrom Withoutundue friction. The conduit is provided lwith rows of perforations 8 and 9 arranged in set-2, one set being at the topof the conduit and the other set at the bottom. The rows in said sets 8 and 9 are staggered so that they will discharge into different vcells ofthe muiller. At the left hand end of the .conduit the orifices or holes areJr-nore numerous than at the right hand end. .In other Words,`the exhaust gases are permitted to enter the rst cell' of the muffler more freely than to the subsequent cel-ls, and the .distance traveled by those entering the first cell will be considerl ably greater than those entering the later cells. This has th'e eect of lagging the exhaust gas impulses from the engine one be- I hind the other, whereby a breathing or hissgas passages between the conduit and the' cells step-by-stepI as the dist-ance from the inlet increases. From a manufacturing point of vview it is simpl-er te use the same` size holes and vary their numher'than to change the diameter for each cell.I I

The ends of the conduit are screw threaded one to receive the head 10 and a coupling `to connect it to thejexhaust `manifold, the

Each diaphragm is provided withl 'acentral I opening .of substantially the same diameteras the conduit and through which the latter extends. The peripheral portion -of each diaphragm is provided with an annular ortion 1-3 formed integral therewith w ich acts as a spacing device to hold the same in position. These diaphragms are made out of relatively thin sheet metal vand are pressed into cup-shaped form shown by any suitable and well known means. Each diaphragm is provided with one V -shaped opening or notch 14 to permit exhaust gases to flow from one cell or chamber to another cell or chamber on the oppositeside of the diaphragm. The V -shaped openings or notches may be and preferably are formed by a stamping operation at the time the diaphragm is formed and previous to the formation 0fthe annular spacing devices 13. In order to effectively break `up the lgas impulses and cause one part to tag behind another and to form a tortuousv or zigzag path 'gularly displaced. is located at the bottom of one diaphragm.

therefor, the V-sha'ped openings 14 are an- As shown an orifice 14 and a similar orifice 14; at the top of the adjacent diaphragm, so that exhaust gases passinxcr from the` holes S first How upward iutoeell then dt'nrnu'ard.on both sides of the conduit 7 and through the orifice Minto 'hev cell 1(,l,1\d'so on.'4 It will be noted, thateaeh eelhin addition to conveying exhaust .gases from one celltoanother, also receives exhaust gasesthrough one row orthe other ot the orifcesin the conduit 7.

In order toseeure the diaphragms in place,

. two or more rods 17 are prorided, which are made' in the form eff licita, the heads beingr mounted in the. head or .flange 10. The right. hand ends of the rods, extend through `a he'ad18, and arc/held in place by nuts. This head is provided with a. suitable discharge' opening 19, t at. is of sutlicient. size to per- `1nit the gases issuing,r from the final cell to freely escape.

In order to prevent the 'diaphragms Vfrom moving bodilyalong^ the' rods 17. and also tov permit the parts to expand and contract under temperature changes. two of the rods..

such as 20 and 21. are provided with small spacingY devices 22, made 1n Vthe form of rings. These rmgsmeshpped into pla'ce between the diaphragms when the latterare assen'ibled. Near the right handendof each of these rods; isa coiled ,compressionspring;r 2?., which p e1fn1its`"tliepai`ts toxe-X'pand and contract under temperaturef'ehanges, Said springr bear-iner at one end on the head 1S and on the end disk Qt at. the other. The

A disk il acts as a diaphragmQand isprefer- .tlanjrfe or sparingr device 153 ably madea little thicker than thc other diaphragms on aeeount of the fact that. it. is pressed by the spring 2.3 against. the. annularof the adjacent. diaphragm.

Surroundingr the diaphragms and seatedv in annular ,shoulders in thel heads .l0 and 1S is a cylindrical easingr 23 that is made ofV thin sheet. metal. said easing preferably making"r a close til with the. peripheral sul,

faces of the several diaphrznfms so as to prevent, leak s aees` and canse tlr(` e,\'- hanst `aars-lo Il Ziff/.HLP fashion hereinlwt'ore4 referred to. l

l hare shaun the 'mntller asdneingf pro'A vvrided with a water jacket. whiehmay be 'used or not as the' conditions of service diethrough the eellst in the different 'outputs eit-herjtwo or four cycle.j 'and this uithout creating any 'substantial back pressure thereon. By changing' the number of cells, the length of'. conduitf? and the. number of sets 0f oriticestherein the muffler can bc used on engines having widely different outputs. As will be readily appreciated it. is of material advantage toA be able to use low costfpunehings, that can be made up in quantities `and afterward asf sembled to `t'orm a mutlier haring a greater or less number of cells, depending upon the size and character of the engine to bemuffied.

Instead of changing' the dimensionsof the parts for use with larger engines I prefer t-o so construct. the muffler that it will satisfactorily mutlle exhaust. gases of say a 25 kw.,

and when itI is desired to muflle the exhaust` Agases of a larger vengine to arrange, twoor., more of these mnfilersin multipleas regards the discharge of frases. Suchan :1rrangement is shown `in Fie. 6 wherein 34, 35

.and 436 indicatel mutllers otith'e, character pre- 'viously described. To eah of lthese mufers is connected ashort conduitthat is oonnected A'to a distributing derice or header' 37,' the hitter bein: connected 'a pipe 38 to the exhaust. manifold of the engine. Vith this arrangement a supply of innfflers can be keptI in stock and one or moho sent. dut with each engine, dependingr upon the output of the. lat-ter. i

(lne of the rer'r important features of my 110- iniprored nmlller residesl inthe Vl'aet. that'the whole rolume of j "as does' not pass through all of the eells. small perth n of'the gas passes through all of the eellpt .\nnther small portion passes through hasta than the total nnmlrer of cells. while a third `small portion passes'tlllolrlli a .still less 'niimlufr of. cells and so en, the number \l'.\.lflis being .sin-cessirel'r drrreased. and heure tlte lengths of the llas passa 'es for. the dil'ereut impulses sneeessirelr leerease. AThisl l'esnltsiir breaking' up the total amount of :fai: from a given exhaust or discharge into a la' f her of parts which are retarded in tui-ir linal exit one behind the other. 1 ln accordance with the provisiones of the patent statutes, l hare described the-principle of operation of in v invention, touether with the. apparatus which I now consider to represent the liestembodiment thereof; but I desire to have it understood that the apparatus shown is only illustrative, and that the invention can be carried out by other means.

What I claim as new and desire to secure by ILeiters Iatent of thelUnited States, is z- 1. In a muler, nthe combination of a conduit. having gas discharging orifices which decrease in cross sectional area toward the point of final discharge, a casing, diaphragms which surround the conduit and di` vide the casing into cells that- Communigate with the orifices'to afford gas passage@ of different lengths, said diaphragms having openings forming passages, the opening in one diaphragm being angulaily displaced With respect to those of the adjacent diaphragms to cause the gases to follow a zigzag path, means for closing the endsof the casing, and means for holding the parts together.

2. In a mufiier, the combination ot a con duit having suitably spaced gas` discharge orifices, a casing, diaphragms surrounding the conduit for dividing the casing into cells that receive gas in multiple from the orifices to afford gas passages of different lengths, each of said diaphragms being provided with an opening, said openings being displaced angularly so that the gas follows a double zigzag path in flowing from one cell to its adjacent cell, the volume of gas in the several cells increasing from the initial toward the final cell.

3. In a mufiier, the combination ot' a conduit having staggered discharge orifices that open into alternate cells, a casing, partitions each having an opening near its periphery forming a-passage for gas, said partitions dividing the casing perpendicularly into cells through which the gas Hows from the passages in a double zigzag path, the volurne of the gas in the several cells increasingV step-by-step, heads for the casing, retaining means for the partitions which areseated in the heads, one of said heads being supported by the conduit, and the other by the means.

4. In a mufier, the combination of a conduit which is closed atl one end and receives exhaust gases at the other. said conduit having` sets of discharge orifices that decrease in area toward said closed end to deliver different amounts of gas to the cells` a cas ing, perforated diaphragms thatl divide the casing into cells, alternate cells communicating with the same set of orifices, the perforations in adjacent diaphragms being angularly displaced to cause the gases to flow in a double zigzag path.

iin@ Vthe dia hra ms from nu on the conduit, cup shaped sl'lieet m( fal diang i1 to cells perf/c ations, heral notches ans preventring With respell t) the conduit, and springsl located be'- tween one of t-he heads and a diaphragm t0 compensate for expansion Iand contraction.

6. In a muffler, the combination of a perforated exhaust conduit whose perfcrations decrease in cross-sectional area toward the outer end, a casing, a pair of heads th at support the casing, one of which is mounted Von the conduit, cup shaped sheetl metal dia phragms which divide theA c that communicate with L4h said diaphragms having per that are angularly displaced, i;

phragms which divide the casing into cells that communicate with the perforations, said diaphragms having peripheral notches that are angularly displaced, means that enter the heads and prevent the diaphragms from moving withrespect to the conduit, and a water jacket which surrounds the casing and is supported by the heads thereof.

7. In a mufiier, the combination of an exhaust conduit containing perforations that f decrease in area toward one end, a head that is fixed in position onv the conduit, rods mountedin the heads, thin metal diaphraglns that are mounted on the conduit and rods and are spaced apart to form cells that communicate with the perforations, a second head, spring means located between the second head and one of the diaphragms to subject the latter to pressure, and a 'casing that surrounds the diaphragms and is.

supported by the heads.

8. In combination, an exhaust conduit,I

plurality of separate mufliers connected" thereto in multiple relation as regards thej flow of gas and discharging individually, each of said mufilers comprising a cellular structure with angularly displaced passages between cells, a conduit, and orifices in the conduit arranged to simultaneously supply gas to the different cells in multiple whereby each gas impulse is broken up into parts and said parts -are lagged one behind the other. In witness whereof, I have hereunto set my hand this 27th day of December, 1912.

MALGOLM THOMSON lVitnesses ELIHU THoMsoN, JOHN A. McMANUs, Jr. 

